Rails - Jun 2005 - Access to Controller Objects in Helpers

I don''t know if this is a Ruby or a Rails question, but it has to do
with
the availability of an object in the controller to a helper. Here is the
scenario:

I have an ImagesController class, and of course a image/list view. To help
me display the images uniformly, I wanted to create a helper, much as in
4-Days:

require ''RMagick''

module ImagesHelper
	def self.append_features(controller)
		controller.ancestors.include?(ActionController::Base) ?
			controller.add_template_helper(self) : super
	end
	
	def show_image(alttext, src, ext=''.gif'')
		if src.length > 0 then
			file_name = src.include?(''/'') ? src :
"/#{@request.env}/#{src}"
			img_options = { "src" => file_name }
			img_options["src"] += src.include?(''.'') ?
'''' : ext
			img_options["border"] = "0"
			img_options["alt"] = alttext
			
			#size_of_image(src, ext)
			#img_options["width"], img_options["height"]
@options[src]["width"], @options[src]["height"]
			
			tag(''img'', img_options)
		end
	end

# .

end

Now, in my controller, I use what I believe to be correct...

class ImagesController < ApplicationController
	helper :Images

# ...

The problem in the show_image function occurs when @request.env raises a
name_error exception. Running this with breakpointer I can stop at the top
of show_image and @request sure exists, but not in running code. Any help on
this is appreciated.

Thanks

Steve Ross wrote:
> The problem in the show_image function occurs when @request.env raises a
> name_error exception. Running this with breakpointer I can stop at the top
> of show_image and @request sure exists, but not in running code. Any help
on
> this is appreciated.
The @request is a special instance variable that is not passed to the 
view (and its helpers) in the same way that other user-defined instance 
variables are.

However, you can access @request from the helper or the view by calling 
''controller.request'', as it is exposed thru a
''request'' accessor method.

An alternative would be to assign the @request.env method to a @env 
instance variable in the action method:

def my_action
   @env = @request.env
end

This would make the env hash available to the view and its helpers.

rgds
Dema
-- 
http://dema.ruby.com.br - Rails development from a .NET perspective